Textbox validating event in asp net
The same doesn t happen with textboxes because users can type any text into a textbox by design. IsValid parameter, and you're good to go. You should see something like this: NET controls designed to be editable and creatable on the client and capable of interacting with the event validation subsystem in a custom way. Let's give it a try, and add a RequiredFieldValidator to our page. Invalid postback or callback argument. NET page uses the data in the hidden field to verify that the sender of the event is a registered control and that any post is directed at registered controls and is, in the case of a list control, registered data.